1 FIELD OF THE INVENTION
This invention pertains to a retainer for holding an electrical box, such as an outlet or a switch box, into a wall.
2. THE PRIOR ART
There is a definite need for a low cost general purpose retainer for holding electrical boxes into walls. Electrical boxes used to be all metal, but are now offered in sheet metal, thermoset plastic, fiberglass, and die cast metal. There is quite a diversity of outlet boxes on the market and they are used for open sheated wiring, flexible conduit, and rigid conduit wiring. There are quite a variety of walls that are commonly encountered, such as stud frame and sheet rock of 3/8 to 1 inch thickness, honeycomb panels, wall board, sheet metal, wood paneling, wood stripping, ceiling tile, and concrete blocks to name a few.
Installations of wiring after the walls have been built is a problem; it always has been. It can be very difficult to secure the box especially if it's alongside a stud or structural member. Then there are good reasons to have boxes removably installed. This is very difficult to do. There is a definite need for a single, low cost, small, interchangable and universal, easy to use box retainer that will work in virtually any wall, which will enable removal of the box, and which makes it easy to install a box in existing construction.
Specific examples of previous attempts made at box retainers include:
U.S. Pat. No. 2,736,450 by E. B. Atkinson, 2/28/56, a compression type barb requiring a full depth wall, a fairly precise fit of the box to the wall, and which is not removable. This device will not work in sheet rock, plaster or wallboard. Atkinson has a preformed spring clip that must be made of heavy steel, or else spring steel that has post forming heat treatment. The retainer clip of Atkinson exerts considerable lateral pressure upon the wall and would destroy gypsum board. It appears that the only use for Atkinson is in concrete, brick, solid wood, or metal structures.
U.S. Pat. No. 2,842,281 by H. A. Chisholm, 7/8/58, a spring loaded resilient double detent type of device permanently mounted to a box, works only on a specific thickness of wallboard and will not go against a stud. The box has some free transverse float in the wall after installation. This will not work in varying thickness walls.
U.S. Pat. No. 3,268,189 by J. N. Duchane, 8/23/66, a relatively large bracket for a specific thickness of wallboard, it will not go up against a stud and is quite bulky. It requires precision fitting of the box to a wall opening or the box can move transversely in the opening. This device will not work in paneling or plaster.
U.S. Pat. No. 3,424,332, by D. Pimentel, 1/28/69, has a foldable L-shaped clip for pulling a box cover against the backside of a wall. The clip is unique to the specific cover for which it is intended.
U.S. Pat. No. 3,860,139, A. French et al, 1/14/75, a resilient detent like Chrisholm, which only works in a precise thickness wall and does not give lateral fixing of the box to the wall.
U.S. Pat. No. 4,226,393, J. A. Rardin et al, 10/7/80, a screw together multiple piece assembly of at least three parts to hold a box in a wall. This device is selectively intended for a very small range in wall thickness, requires a relatively precise large opening to be made in a wall. this device is also useable only on a matched box.
U.S. Pat. No. 2,454,119, E. R. Atkinson, 11/16/48, is a one piece electrical box retainer that is slipped in along side of a box. This device does not provide for pulling of the retainer taunt against the wall or for tightening the box in the wall; the box has to be firmly pressed into the wall while the fingers of this device are bent into the box. This device has no provision to make the box rattle free and securely mounted without being sloppy in the wall.